From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Engine performance issues with low-grade fuel, low temperatures in the U.S.A., and potential carburettor and induction system modifications.
| Identifier | WestWitteringFiles\G\June1921\ Scan8 | |
| Date | 8th June 1921 | |
| To R.R. of America Inc. from R.{Sir Henry Royce} -2- R10/G8/6/21 Contd. with low grade fuel, either of our make or any other, will give satisfaction unless the cooling water, and the air under the bonnet is maintained at the highest temperature that it is possible to keep it. Although not affecting the starting, this is very important - (1) for slow running. (2) for equal distribution at slow speeds. (3) for petrol economy. (4) It will also largely meet the complaints such as Knock in the transmission, due to the uneven turning of the engine caused by bad distribution. We believe we know all your important troubles; they exist to a less degree here, and with all care. We can obtain fuel and roads of all grade of badness, but we cannot produce * your extremely low winter temperature, and as these do not exist in U.S.A. at present, it is no use sending anyone or coming to U.S.A. to find them just now. I do not think you or we are sufficiently sure of our conclusions of modifications that should be made for me to give final instructions, but below is given my views of the situation to this date. Short of a complete new design of engine we find there are possibilities of getting better results with the carburettor 'also in the present position, and we are experimenting with the carburettor moved to the exhaust side, but we find this for many reasons, numerous and obvious, very undesirable, and unless we cannot obtain satisfaction without, we shall not recommend changing the carburettor position. It has been proved by Mr. Hives at Derby, that the exact contour of the induction system has a marked effect, so much so that the influence of the internal pipe in the manifold (Contd.) * We did, in the 'tomb' [strikethrough] or 'cold' room into which a complete chassis could be 'soaked' at cold temp. | ||